We point out that the extended Chalker-Coddington model in the ''class
ical'' limit, i.e. the limit of large disorder, shows crossover to the
so-called ''smart kinetic walks''. The reason why this limit has prev
iously been identified with ordinary percolation is, presumably, that
the localization length exponents nu coincide for the two problems. Ot
her exponents, like the fractal dimension D, differ. This gives an opp
ortunity to test the consistency of the semiclassical picture of the l
ocalization-delocalization transitions in the integer quantum Hall eff
ect. We calculate numerically, using the extended Chalker-Coddington m
odel, two exponents tau and D that characterize critical properties of
the geometry of the wave function at these transitions. We find that
the exponents, within our precision, are equal to those of two-dimensi
onal percolation, as predicted by the semiclassical picture.